summaryrefslogtreecommitdiff
path: root/print-igrp.c
blob: fbb313427c72026ce5795ec508fe9618e33c48a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
 * Copyright (c) 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Initial contribution from Francis Dupont (francis.dupont@inria.fr)
 */

#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include "interface.h"
#include "extract.h"			/* must come after interface.h */

/* Cisco IGRP definitions */

/* IGRP Header */

struct igrphdr {
	uint8_t ig_vop;	/* protocol version number / opcode */
#define IGRP_V(x)	(((x) & 0xf0) >> 4)
#define IGRP_OP(x)	((x) & 0x0f)
	uint8_t ig_ed;		/* edition number */
	uint16_t ig_as;	/* autonomous system number */
	uint16_t ig_ni;	/* number of subnet in local net */
	uint16_t ig_ns;	/* number of networks in AS */
	uint16_t ig_nx;	/* number of networks ouside AS */
	uint16_t ig_sum;	/* checksum of IGRP header & data */
};

#define IGRP_UPDATE	1
#define IGRP_REQUEST	2

/* IGRP routing entry */

struct igrprte {
	uint8_t igr_net[3];	/* 3 significant octets of IP address */
	uint8_t igr_dly[3];	/* delay in tens of microseconds */
	uint8_t igr_bw[3];	/* bandwidth in units of 1 kb/s */
	uint8_t igr_mtu[2];	/* MTU in octets */
	uint8_t igr_rel;	/* percent packets successfully tx/rx */
	uint8_t igr_ld;	/* percent of channel occupied */
	uint8_t igr_hct;	/* hop count */
};

#define IGRP_RTE_SIZE	14	/* don't believe sizeof ! */

static void
igrp_entry_print(netdissect_options *ndo, register struct igrprte *igr,
    register int is_interior, register int is_exterior)
{
	register u_int delay, bandwidth;
	u_int metric, mtu;

	if (is_interior)
		ND_PRINT((ndo, " *.%d.%d.%d", igr->igr_net[0],
		    igr->igr_net[1], igr->igr_net[2]));
	else if (is_exterior)
		ND_PRINT((ndo, " X%d.%d.%d.0", igr->igr_net[0],
		    igr->igr_net[1], igr->igr_net[2]));
	else
		ND_PRINT((ndo, " %d.%d.%d.0", igr->igr_net[0],
		    igr->igr_net[1], igr->igr_net[2]));

	delay = EXTRACT_24BITS(igr->igr_dly);
	bandwidth = EXTRACT_24BITS(igr->igr_bw);
	metric = bandwidth + delay;
	if (metric > 0xffffff)
		metric = 0xffffff;
	mtu = EXTRACT_16BITS(igr->igr_mtu);

	ND_PRINT((ndo, " d=%d b=%d r=%d l=%d M=%d mtu=%d in %d hops",
	    10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
	    igr->igr_rel, igr->igr_ld, metric,
	    mtu, igr->igr_hct));
}

static const struct tok op2str[] = {
	{ IGRP_UPDATE,		"update" },
	{ IGRP_REQUEST,		"request" },
	{ 0,			NULL }
};

void
igrp_print(netdissect_options *ndo, register const u_char *bp, u_int length)
{
	register struct igrphdr *hdr;
	register u_char *cp;
	u_int nint, nsys, next;

	hdr = (struct igrphdr *)bp;
	cp = (u_char *)(hdr + 1);
	ND_PRINT((ndo, "igrp:"));

	/* Header */
	ND_TCHECK(*hdr);
	nint = EXTRACT_16BITS(&hdr->ig_ni);
	nsys = EXTRACT_16BITS(&hdr->ig_ns);
	next = EXTRACT_16BITS(&hdr->ig_nx);

	ND_PRINT((ndo, " %s V%d edit=%d AS=%d (%d/%d/%d)",
	    tok2str(op2str, "op-#%d", IGRP_OP(hdr->ig_vop)),
	    IGRP_V(hdr->ig_vop),
	    hdr->ig_ed,
	    EXTRACT_16BITS(&hdr->ig_as),
	    nint,
	    nsys,
	    next));

	length -= sizeof(*hdr);
	while (length >= IGRP_RTE_SIZE) {
		if (nint > 0) {
			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
			igrp_entry_print(ndo, (struct igrprte *)cp, 1, 0);
			--nint;
		} else if (nsys > 0) {
			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
			igrp_entry_print(ndo, (struct igrprte *)cp, 0, 0);
			--nsys;
		} else if (next > 0) {
			ND_TCHECK2(*cp, IGRP_RTE_SIZE);
			igrp_entry_print(ndo, (struct igrprte *)cp, 0, 1);
			--next;
		} else {
			ND_PRINT((ndo, " [extra bytes %d]", length));
			break;
		}
		cp += IGRP_RTE_SIZE;
		length -= IGRP_RTE_SIZE;
	}
	if (nint == 0 && nsys == 0 && next == 0)
		return;
trunc:
	ND_PRINT((ndo, " [|igrp]"));
}